Biology

Biology

The common wallaroo is often solitary, occupying a relatively small, stable home range near to a rocky outcrop or water, and moving out of rough country to graze on grasses and shrubs in adjoining areas (2) (4) (9). Small groups sometimes form around favoured resources, but are usually quite loose in size and composition (2) (6). The common wallaroo is able to survive harsh conditions by using caves and rocky outcrops for shelter, and appears to be able to go for as much as two to three months without drinking, surviving solely on the water contained in food plants (2) (9). The common wallaroo is believed to be polygynous (6) and is an opportunistic breeder, able to breed throughout the year, although often ceasing reproduction during prolonged droughts (2) (8) (10). A single, tiny young is born after a gestation period of 30 to 38 days (8), after which it climbs, unaided, through the female's fur and into the pouch, where it attaches to a teat and begins to suckle (11). Most development takes place within the pouch, the young common wallaroo emerging after around 231 to 270 days (8). The young is suckled for at least 12 to 14 months, with males reaching sexual maturity at around 18 to 20 months in captivity, and females at 14 to 24 months (8). Individuals may live for over 18 years in the wild (2). In a process known as embryonic diapause, the female common wallaroo is able to become pregnant again shortly after giving birth. However, the new embryo remains dormant until the first young is ready to leave the pouch or is lost, after which the embryo resumes development and is born when the pouch is vacant. This unusual form of reproduction, found in many kangaroos, means the female can quickly replace young lost to predators or drought, and can have embryos ready to develop as soon as conditions become favourable (2) (11).